Countries in the euro zone posted a €15.4-billion trade surplus in May, with Germany again leading the way.

Exports in May across the 18-nation single currency zone rose by 0.6% in May compared with April while imports were up 0.5%, the Eurostat statistics agency said.

The data provided "slightly brighter news after a series of disappointing hard data releases for the month," said Christian Schulz of Berenberg Bank.

"However, trade activity has been largely flat-lining so far this year as emerging market weakness weighed on exports and a relatively mild winter lowered energy imports," Mr Schulz added.

The full 28-nation EU showed a small surplus of €600 million in May, down from 1.0 billion in April and sharply lower than the €15 billion in May 2013.

Capital Markets economist Michael Pearce warned that euro zone exports still faced powerful headwinds from a strong euro. 

"Today's data showed that the pace of recovery in the euro zone's external sector remains gradual at best. And with the euro remaining at high levels, we still think the European Central Bank has more to do to bring the currency down and help rouse the eurozone economy."

Germany posted the biggest trade surplus for the four months to April, at €66 billion, followed by the Netherlands, Ireland and Italy.

Britain, where a recovery is stoking demand for imports, posted the biggest deficit, at €38.8 billion for the four months, followed by France, Spain and Greece.